1. Field of the Invention
This invention relates to a client-optimized data transmission system and method in various transmission environments in which many computers of various kinds are mutually connected. Particularly, this invention relates to a data transmission system and method which satisfies users accessing a data transmission service.
2. Description of the Related Art
Since data networks among computers, e.g., the Internet, have become popular, data providing services, e.g., World Wide Web (WWW), have also become popular. In a data providing service, data to be provided is loaded on a server computer (a server, hereinafter) which is connected to the Internet, and a large number of general users, i.e. client computers (clients, hereinafter) are connected to the server via the Internet. The clients request the server to transmit data and obtain the data.
Normally, in the WWW, a current WWW server sends the same data at the request of a client regardless of the condition of a transmission line which connects the server and the client and regardless of the client's ability to receive and process the data. Otherwise, the WWW server requests the client to select a data set, and sends the data set to the client.
In this method, even when lines are busy or the client is a wireless terminal with a very low transmission rate or the client does not have an image display function, unnecessary data, e.g., image data for a client which does not have an image display function, is sent to the client. This is irritating for the users. Therefore, the users often give up obtaining data from the WWW.
A conventional technique for controlling a transmission rate between computers is disclosed in Japanese Unexamined Published Patent Application SHO 60-59841. More particularly, SHO 60-59841 discloses a technique which optimizes a transmission rate between the computers by obtaining a desired transmission rate from a receiving computer and transmitting data at the desired transmission rate of the receiving computer.
In Japanese Unexamined Published Patent Application HEI 6-224877, a conventional technique for controlling a number of transmission lines based on an amount of data to be transmitted is disclosed.
As discussed above, conventional servers, such as the WWW server send data to the client regardless of the transmission rate of the line between computers and the ability of the client. This causes inconvenience for the users. This invention intends to solve such inconvenience for the users accessing data providing services.